Compound (I) is a useful compound for the therapy of the abnormality of lipid metabolism as an agonist of human peroxisome proliferator-activated receptor (PPAR), in particular, as an agonist of human PPARα isoform, and has been prepared through a process disclosed in Jpn. Kokai Tokkyo Koho JP 2001-55367.
Preparation of the compound (I) on an industrial scale as a medicinal drug lies in the finding of crystals homogeneous and excellent in the stability and yet the establishment of a preparative process thereof.